Why not show both? Wikipedia could display archive links alongside original sources, clearly labeled so readers know which is which. This preserves access when originals disappear while keeping the primary source as the main reference.

The objection is to this specific archieve service not archiving in general.

They generally do. Random example, citation 349 on the page of George Washington: ""A Brief History of GW"[link]. GW Libraries. Archived[link] from the original on September 14, 2019. Retrieved August 19, 2019."